Method of demagnetizing watches



(No Model.)

J. GREAVES.

METHOD OF DEMAGNETI-ZING WATQHES, 850.

No. 397,423. Patented Feb. 5, 1889.

Eve]? to 1-;

N PETERS. Phom-Llihogmphor. Waslunglon. D. c.

UNITED STATES PATENT OFFICE.

.l'OHk GREAVES, OF ST. LOUIS, MISSOURI.

METHOD OF DEMAGNETlZlNG WATCHES, 84,6.

SPECIFICATION forming part of Letters Patent No. 397,423, dated February 5, 1889.

Application filed May 14,1888. Serial No. 273,76. (No model.)

To aZZ whom it may concern Be it known that l, JOHN GREAYES, ot' the city of St. Louis, in the State of Missouri have invented a certain new and usei'ul' Method of Demagnetizing \Vatchcs, &c., of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification.

The invention relates toa means, method, or process of demagnetizing watches and other articles which have been rendered magnetic by broken lines in the succeeding positions;

and Fig. II is a perspective view showing the watch in front of the magnets in the act of passing it through the angles of the magnetic field.

1 is an electro-magnet having poles 2.

3 is the watch, which is first held in the position shown by full lines in Fig. I. It is then slowly moved from this first position around the magnet in the direction of the dotted line 6 7, thereby passing through the angles of magnetic force to a point (at or near 7) that. neutral, or a point where the needle of a compass will play free in a line in the direction of the current of electricity, In some cases the watch moved in the directions indicated by full line 9 10 in Fig. II, which, it will be seen, will change the position of the watch relatively to the lines of magnetic force. This may be done when there is only a small amount of magnetism in the watch.

One or more magnets may he used, and a mechanism is employed for producing a re verse mm'cment of the circuit through the magnets-as, t'or instance, such a mechanism as is shown, described, and claimed in my application filed August 11), 1887, Serial No. 240,988, allowed January 12, 18%.

I have discovered that this method oi placing the watch or other article in the magnetic field and then passing it through the angles of magnetic force to a neutral point while the current is alternately and continuously rcycrsed through the magnet produces results that are not had in any other method, as it ettectually demagnetizes the watch orartiele, and generally with but one operation.

I claim as my invention The improved method of demagnetizing articles herein shown and described, consisting in placing the article in the magnetic field and then passing it through the angles of magnetic force to a neutral point, as specified.

JOHN GREAYES.

In presence of BENJN. A. KNIGHT Jos. WAIILE. 

